Method for the production of a mixture with constant component composition made of several starting materials, and a regulating device for carrying out the method

ABSTRACT

A method of producing a mixture with constant component composition from a plurality of starting materials, each of which contains a portion of the components of the required composition, the starting materials being premixed in dosages, preferably analyzed by an X-ray fluorescence process and supplied to a homogenization means, the dosaging of the starting materials further taking place within a predetermined dosage range in dependence upon the premixture component composition established in the analysis and under maintenance of predetermined component proportions, while upon passing beyond the predetermined dosage range of one of the starting materials upwardly or downwardly, at least one of the predetermined component proportions is stepwise changed until the predetermined dosage range has been restored. The invention also includes means for carrying out said method.

nite States Patent 1191 Wildpaner Sept. 17, 1974 Primary Examiner-Robert G. Nilson Attorney, Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson [57] ABSTRACT [75] Inventor: Hubert Wfldp n A method of producing a mixture with constant com- Bensberg-Frankenf t, Germany ponent composition from a plurality of starting materi- I als, each of which contains a portion of the compo- [73] Asslgnee' itt g g f nents of the required composition, the starting materitlengese Sc 3 0 Germany als being premixed in dosages, preferably analyzed by [22] Filed; Nov, 13, 1972 an X-ray fluorescencehprocess and supplied to a homogenization means, t e dosaging of the starting ma- [21] Appl 306040 terials further taking place within a predetermined dosage range in dependence upon the premixture [30] Foreign Application Priority D t component composition established in the analysis Nov 13 1971 Germany 2156498 and under maintenance of predetermined component proportions, while upon passing beyond the predeter- 52 us. c1 137/3, 106/100, 137/93 mined dosage range of one Of the Starting materials 151 1m. 01.; C04b 7/38 upwardly or dOWYlwafdlY, of t predeter- [58] Field of Search 137/3, 5, 93; 106/100 Component Proportions stepwlse changed until the predetermmed dosage range has been re- [56] References Cited stored .dThe ilnvgeintion also includes means for carrying UNITED STATES PATENTS out met 0 3,602,488 8/1971 Romig 106/100 10 Claims, 1 Drawing F g e EVC CONVEYOR N li fil l I CALCULATOR Ki 1 I?! Z R P9 6;: A64 1' l 2 3 Q11 4 ghelT GOVERNOR INTEORATOR l 9 8 7{ coi mron SECi E as 511 G,- INTEGRATOR K THEORET1CAL6\ VALUE INDICATOR 17 *AV 1 INTEGRATORS 1U r "1 1 V 7a 211111 Kr time? u NIT I gAl/rr 3\ I 19 l --\LOBIC V LIW Ve /,s 75 e,r=l.....3

ALARM \76 DEVICE PAIENIEDSEP 1 T1874 02322 man METHOD FOR THE PRODUCTION OF A MIXTURE WITH CONSTANT COMPONENT COMPOSITION MADE OF SEVERAL STARTING MATERIALS, AND A REGULATING DEVICE FOR CARRYING OUT THE METHOD This invention relates to a method for the production of a mixture having constant composition of components made of several starting materials, which contain in each case at least one part of the components of the required composition, whereby the starting materials are previously mixed dosaged, advantageously analyzed by means of a method of X-ray fluorescence and conveyed to a homogenization device, whereby furthermore, the dosaging of the starting materials in each case takes place within a presumed range of dosage in dependence upon the content of components determined in the analysis of the pre-mixture during maintenance of predetermined component proportions.

A known method for the production of a mixture having constant composition out of several starting materials containing different components provided that the component contents of the pre-mixed starting materials were compared with component contents of a required mixture, rigidly prescribed in a precise manner. From the resulting deviations, the dosages of the individual starting materials were in each case determined for the premixture. This method fulfilled the object only to an insufficient extent of producing a mixture of constant composition of components, as upon strong fluctuations in the component contents of the individual starting materials, the corresponding ranges of dosage were partially exceeded or fallen short of. The adaptation to the altered component contents of the starting materials was to be carried out only with difficulty in the known method of mixture.

It is the object of the invention to improve the known method. In accordance with the invention, the problem is solved thereby, that after exceeding or falling short of the prescribed range of dosage of at least one starting material, one at least of the prescribed component proportions is gradually altered for as long until the prescribed range of dosaging is again regulated. The alteration in accordance with the invention of the prescribed component proportions insures that the component contents prescribed for the mixture are altered only by small amounts, whereby the corresponding dosage-determinations of the starting materials may simply be decided anew.

Through the newly regulated dosages in each case therefore the component'fluctuations of the premixed starting materials may be automatically equalized.

In development of the invention, it is provided that for the adjustment of the prescribed dosaging range the component proportions are altered gradually in each case in prescribed ranges by corresponding amounts in sequence, advantageously starting with the component proportion which brings about the least alteration of the composition of the pre-mixture, and that subsequently in similar manner in each case the component proportion is altered with the next greater influence on the composition of the pre-mixture during simultaneous alteration of that component proportion with the less influence, whereby the component proportion with the lower influence in each case is scanned or explored over the entire given range. The advantage consists therein, that through this measure, the characteristics required of a mixture which are given essentially through the component contents may be maintained in a precise manner. Particularly through this sequence, that component ratio with the greatest influence on the mixture in determined ranges is altered after the others have been altered, so that the alterations brought about through a control action cause only slight exceeding or falling-below of the theoretical value.

In addition, in development of the method according to the invention, it is provided that upon the alteration of the prescribed component proportions, a component-residue content is taken into consideration. Through this measure, above all the impurities in the premixture are taken into consideration in the determination of the prescribed component contents for the mixture, so that the disadvantage of having component contents precisely fixed for the maintenance of the prescribed component ratios may be departed from or eliminated. In addition, it is suitable that the component-residue content is determined from the components ascertained in the analysis, whereby the component contents averaged are summed up and subtracted from the total content and that the residue content determined is equalized preferably through formation of an average or mean value. In this manner, in an advantageous way it is attained that the fluctuating impurities in the pre-mixture have only minor influence on the prescribed component contents and accordingly on the dosaging in each case of the starting materials. The component ratios in the homogenizing device thereafter build up very rapidly to the required values, so that the mixture of constant component-composition is attained after a brief operating time.

A further development of the method according to the invention provides that exceeding or falling-short of the prescribed range of at least one starting material, whereby the component ratios in each case have already been altered in their total range, alarm signals are switched on. In this way, in simple manner the production of an incorrectly composed mixture will be prevented and the cause of the incorrect composition of the starting materials determined.

The invention relates in addition to a regulating device for the carrying out of the method in accordance with the invention, which has a controlled system, a setting means or theoretical-value-indicator and a governor or controller, whereby the controlled system has in addition to conveyorand premixing-machinery an X-ray-fluorescence-analyzing device, the theoreticalvalue indicator contains a calculating unit for the determination of the component contents from the component-proportions and whereby the governor contains measuringand theoretical-value equalizers and a calculating unit for the determination of the dosages of the starting materials within prescribed ranges of dosage. In accordance with the invention, there is arranged between the governor and the theoretical-value-indicator a (mathematical) logic-unit which is connected on the one side when exceeding or falling short of the prescribed dosage range of at least one starting material occurs with devices which alter the component-ratios Vr. Control units are connected to the setting means. Through the arrangement according to the invention of a logic-unit for the constant examination of the dosage ranges of the starting materials, a reliable control is present as to whether a change of the component ratios must be undertaken in predetermined ranges, in order to insure a prescribed mixture.

It is suitable that the logic-unit is connected with a control unit for the gradual alteration of the component ratios Vr,r 1" with the lowest influence on the composition of the pre-mixture. Through this measure only a slight application of influence upon the method of mixture is necessary, so that accordingly the component proportions with the next greater influences upon the mixture do not need to be altered.

Further features of the invention may be inferred from the explanation of the method according to the invention on the basis of a block diagram.

The regulating device for carrying out the method contains a setting means 1, a theoretical-valueindicator 6 and a governor or controller 7. The setting means 1 has in addition to conveyorand pre-mixingdevices 1, 1" for the starting materials, an X-rayfluorescence-analyzing device 2, with which the component contents Ki of the pre-mixture are analyzed, determined in a calculating unit 3 and imparted to the governor or controller 7.

The theoretical-value-indicator 6 consists of a calculating unit for the determination of the prescribed component contents Ks from the prescribed componentratios Vr. The component contents Ki are fed by unit 2 and averaged in the calculating unit 3 and the component contents Ks prescribed by the theoretical-value-indicator 6 are connected with the governor or controller 7 and compared with one another in a comparator unit 7 The deviations in component content t AKi" are connected with a calculating unit 7 for the determination of the deviations in amounts i AGi. The regulated amounts Gi" and the material-deviations i AGi are summed in an integrator 8 to new material quantities Gi i AGi and connected with a logic-unit 9.

The logic unit 9 is arranged between the controller 7 and the theoretical value indicator 6, whereby the logic unit 9 is connected on the one side after exceeding or falling short of the quanity range of at least one starting material with devices, which alter the component proportions Vr. These may be control units. Unit 9 is also connected with the setting means. Thus, the logic unit 9 is first connected with a control unit 10 for the gradual alteration of the component proportion Vr, r 1" with the least influence on the composition of the premixture.

Suitably the control unit 10 is connected with a logic unit 1 l, which has an output connected when the material exceeds or falls short of the controlled admissable range of proportion with a control unit 12 for the gradual alteration of the component ratio Vr, r 2 with the next greater influence on the composition of the premixture. Unit 11 is also connected with an integrator 17 with which the prescribed component ratio Vr, r l" with the least influence is connected.

A logic unit 13 is connected to the output of control unit 12, to receive an input when the material falls short of the corresponding controlled permissible proportion range. A control unit 14 is connected to unit 13 for the gradual alteration of the component ratio Vr,r 2" with greater influence on the composition of the premixture. Unit 13 is also connected with an integrator 18, with which is connected the prescribed component ratio Vr,r 2 with the next greater influence.

It is intended that control unit 14 be connected with a logic unit 15, when material compositions exceed or fall short of the corresponding controlled permissible ratio range. Unit 15 is connected with an alarm device 16, on the other side is connected with an integrator 19, with which the prescribed component ratio Vr,r 3 with the greatest influence is connected. There is connected to the integrators 17, 18, 19 a calculating device 5 for the determination of the prescribed component proportions Vr. Device 5 is connected with the X-ray-fluorescence analyzing device 2 and to a measuring device B, not shown in greater detail, for the premixture-charge B.

In suitable manner, the integrators 17, 18, 19 are connected to the theoretical value indicator 6, which also receives an input from a device 4 for the determination of a component residue content Rg." Device 4 is a calculating device, which is arranged between the theoretical value indicator 6 and a calculating device 3. Calculating device 3 determines the mean value Ki of the component contents Ki of the premixture determined in the analysis. The residue-contentcalculating device 4 includes an integrator 4', which sums up the partial contents Ki of the components, and also includes a differential device 4", which subtracts the summed up partial contents from the total content and further includes an equalization device 4" which averages the residue content R.

The manner of operation of the regulating device is described in the following in greater detail:

At a predetermined point of time t, the component contents of the starting materials are altered in stages. According to the idle time of the setting means, the new component contents Ki of the premixture are determined with the aid of the X-ray-fluorescence analyzing device 2. The component contents Ki" averaged with the aid of the calculating device 3 are furnished to the controller 7 together with component contents Ks prescribed by the theoretical value indicator 6 for the premixture and compared with one another in a comparator unit 7. The deviations of the component contents i AKi are furnished within the governor 7 to a calculating device 7" by unit 7 for the determination of the quanity deviations i AGi for the individual starting materials. The quanity deviations are summed up each according to its indication in the regulated quanities Gi in an integrator 8. The resulting quanities Gi AGi are controlled by the logic unit 9 in each case to their prescribed quanity range. If the prescribed quanity range of at least one starting material is exceeded or falls short then the logic unit 9 a searching-operation is started which alters the prescribed component ratios Vr and those controlled by the theoretical value indicator 6 within predetermined limits until the prescribed quanity range must again be regulated. The prescribed component proportions Vr are determined on their part with the aid of the calculating device 5, whereby the calculating component contents Ki analyzed by the X-ray fluorescence device of the premixture are weighed for the determination of the component ratios of the mixture already present with the premixture charge B in each case and compared with the component ratios Ve regulated for the mixture. The resultant correctional value is summed up for the formation of the prescribed component ratio Vr" to obtain the adjusted component ratio Ve.

When the logic unit 9 has started search operation, a control unit alters the component ratio Vr, r l with the least influence on the mixture to a prescribed amount gradually, by the prescribed value of the component ratio until a logic unit 11 decides whether with this search operation the upper and lower limits of the component ratio Vr,r 1 has been attained. The corrections in each case i AVr,r= 1 are added or subtracted each according to its designation in an integrator 17 to the prescribed component ratio Vr,r l. The newly determined ratio Vr i AVr,r I assumed to exist is imparted to the theoretical value indicator 6 which determines new component contents Ks to be prescribed which are furnished to the controller 7. With the new componen t c9nten t Ks again the quantities GiiAGi are determined for the individual starting materials and examined in the logic n t 9- In order to maintain the fluctuations of the impurities in the component contents Ki of the premixture as low as possible, upon calculating the prescribed component contents Ks from the component ratios Vr, a component residue content Rg is taken into con sideration, which is adapted to the premixture in each case. For the determination of this residue content, the component contents Ki averaged by the calculating device 3 are summed up in the integrator 4, and subsequently in the differential unit 4", the difference must be calculated for the total content. The resultant amount R is averaged in the equalization device 4" to obtain a component residue content Rg.

If the prescribed quanity range of at least one starting material is further exceeded or falls short and the logic unit 11 decides that the upper andlower limit of the adjusting range is exceeded for the component ratio Vr, r l with the least influence, control device 12 alters in a corresponding manner the component ratio Vr,r 2 having the next higher influence until the logic unit 13 decides that the upper and lower limit of this component ratio likewise has been exceeded. In corresponding manner, in an integrator 18 the correction in each case AVr,r 2 is added or subtracted to or from the prescribed component ratio Vr, r 2. For each new operation step of the control device 12, the control device 10 scans or searches within the upper and lower limit gradually for the pertaining component ratio Vr, r 1 by the prescribed value. With the new component ratios Vr i AVr, r l and Vr i AV r, r 2" the prescribed component contents Ks will be determined again in the theoretical value indicator 6. These prescribed component contents will be compared in the controller 7 with the component contents Ki analyzed by the fluorescence analyzing device 2 and averaged in the calculating device 3. New quantities (GiiAGi) will be determined for the starting materials and examined in the logic unit 9.

If the logic unit 9 decides further that the prescribed ggalltilly range of at least one starting material has been exceeded or fallen short and if the logic units 11 and 13 decide that the upper and lower limits of the previous component ratios Vr, r 1; Vr,r 2 have been attained, during search operation a control device 14 alters in corresponding manner the component ratio Vr, r 3" with the greatest influence on the mixture until logic unit 15 decides that the upper and lower limit of this component ratio likewise has been exceeded. If the logic unit 9 determines that the prescribed quantity range of at least one starting material is exceeded or fallen short of, although upon each alteration of the component ratio Vr, r 3" simultaneously the com- The procedure is not limited solely to the described control system with three prescribed component ratios Vr, r 1 3. It may also be used to advantage in a process computer system for measuring different values and giving disturbance-warnings. The process comput'er may with the aid of stored programs take over processing of the component contents Ki delivered by the X-ray-fluorescence analyzing device and their average Ki, the calculation of the component residue content Rg, control the prescribed component ratios Vr, calculate the prescribed component contents fKs and the quantities Gi i AGi and calculate during search operation the component ratios Vr i AVr to be prescribed. In addition, the process computer may produce an output report and give disturbance warnings during the production operation. The process computer contains a control program which utilizes at predetermined time intervals the individual programs required for processing.

What I claim is:

l. The method for producing a mixture having a desired composition including several active different materials which contain at least a part of the components of the required composition, whereby the starting materials are premixed, then the mixture is analyzed by means of X-ray florescence method, conveying said mixture to a mixer, adding, starting material within a prescribed quantity range which depends on the component contents of the premixture setting desired component quantities, comparing individually actual component values with the desired component values, and changing the component ratios of components gradually until the desired quantity of components is obtained wherein the quantity of the components are sequentially altered by adding the component to the mixture which causes the least alteration of the composition of the premixture, and subsequently adding the component to the mixture which has the next greater influence on the composition of the premixture, whereby the quantity of the component with the lesser influence is observed during mixing.

2. The method according to claim 1, wherein the component residue content comprising non-active materials is detected and considered.

3. The method according to claim 2, wherein the component residue content is determined by analysis, whereby the active component percentages are averaged, summed up and subtracted from the total content of the mix and determined residue content mean value is obtained.

4. The method according to claim 1, wherein if the desired quantity range of at least one active starting material cannot be obtained even when the component ratios have been altered over their total range, producing an alarm.

5. A regulating device for controlling the composition of a mixture of active materials and non-active materials comprising, a mixing machine for mixing said materials, a theoretical value analyzer producing a signal for giving desired material ratios, a control device, said mixing machine includes, in addition to conveyor and pre-mixing devices, an X-ray florescence analyzing device, said theoretical value analyzer contains a calculating unit for the determination of the component contents from the desired component ratios, said control device receiving inputs from said theoretical value analyzer and from said X-ray analyzing device and determining the quantities of the active starting materials within prescribed quantity ranges, a logic unit connected between said mixing machine and said control device and supplying an input to said theoretical value analyzer if at least one starting material has a percentage other than desired, wherein said logic unit is connected to gradually alter the component ratio of a first active material Vr, r l which has the least influence on the composition of the premixture, a second control unit is connected to said logic unit, a second logic unit connected to said second control unit and supplying an output to said theoretical value analyzer such that if one component exceeds or falls short of the controlled permissible range ration, a third control unit, which gradually alters the component ratio, a second active material Vr, r 2 with the next greater influence on the composition of the premixture is energized, and an integrator connected to said second logic unit for controlling the component ratio Vr, r 1" having the least influence.

6. A regulating device according to claim 5, comprising a third logic unit connected to said third control unit, said third logic unit determining when the composition of the second material is too great or small, a fourth control unit for controlling the gradual alteration of the component ratio of the material Vr, r 3 with the greatest influence on the composition of the premixture connected to the output of said third logic unit, a second integrator connected to said third logic unit to control the component ratio Vr, r 2 having the next greater influence.

7. A regulating device according to claim 6, wherein said fourth control unit is connected to a fourth logic unit, an alarm device connected to the output of said fourth logic unit, a third integrator connected to the output of said fourth logic device to control the prescribed component ratio Vr, r 3" having the greatest influence.

8. A regulating device according to claim 7, including a calculating device for determining the prescribed component ratios Vr connected to said first, second and third integrators and receiving input from said X-ray fluorescence analyzing device and a premixture charge measuring device connected to said calculating device.

9. A regulating device according to claim 8 in which said first, second and third integrators are connected to said theoretical value indicator, a residue content device for the determination of a component residue content Rg connected to said theoretical value indicator and a calculating device calculating the mean value Ki of the component contents Ki of the premixture determined in the analysis supplying an input to said residue content device.

10. A regulating device according to claim 9, wherein said residue content calculating device includes a fourth integrator which sums up the partial contents Ki of the components and a differential device which subtracts the summed up partial contents from the total content and further includes an analyzing device which averages the residue contents R. 

1. The method for producing a mixture having a desired composition including several active different materials which contain at least a part of the components of the required composition, whereby the starting materials are premixed, then the mixture is analyzed by means of X-ray florescence method, conveying said mixture to a mixer, adding, starting material within a prescribed quantity range which depends on the component contents of the premixture setting desired component quantities, comparing individually actual component values with the desired component values, and changing the component ratios of components gradually until the desired quantity of components is obtained wherein the quantity of the components are sequentially altered by adding the component to the mixture which causes the least alteration of the composition of the premixture, and subsequently adding the component to the mixture which has the next greater influence on the composition of the premixture, whereby the quantity of the component with the lesser influence is observed during mixing.
 2. The method according to claim 1, wherein the component residue content comprising non-active materials is detected and considered.
 3. The method according to claim 2, wherein the component residue content is determined by analysis, whereby the active component percentages are averaged, summed up and subtracted from the total content of the mix and determined residue content mean value is obtained.
 4. The method according to claim 1, wherein if the desired quantity range of at least one active starting material cannot be obtained even when the component ratios have been altered over their total range, producing an alarm.
 5. A regulating device for controlling the composition of a mixture of active materials and non-active materials comprising, a mixing machine for mixing said materials, a theoretical value analyzer producing a signal for giving desired material ratios, a control device, said mixing machine includes, in addition to conveyor and pre-mixing devices, an X-ray florescence analyzing device, said theoretical value analyzer contains a calculatinG unit for the determination of the component contents from the desired component ratios, said control device receiving inputs from said theoretical value analyzer and from said X-ray analyzing device and determining the quantities of the active starting materials within prescribed quantity ranges, a logic unit connected between said mixing machine and said control device and supplying an input to said theoretical value analyzer if at least one starting material has a percentage other than desired, wherein said logic unit is connected to gradually alter the component ratio of a first active material ''''Vr, r 1'''' which has the least influence on the composition of the premixture, a second control unit is connected to said logic unit, a second logic unit connected to said second control unit and supplying an output to said theoretical value analyzer such that if one component exceeds or falls short of the controlled permissible range ration, a third control unit, which gradually alters the component ratio, a second active material ''''Vr, r 2'''' with the next greater influence on the composition of the premixture is energized, and an integrator connected to said second logic unit for controlling the component ratio ''''Vr, r 1'''' having the least influence.
 6. A regulating device according to claim 5, comprising a third logic unit connected to said third control unit, said third logic unit determining when the composition of the second material is too great or small, a fourth control unit for controlling the gradual alteration of the component ratio of the material ''''Vr, r 3'''' with the greatest influence on the composition of the premixture connected to the output of said third logic unit, a second integrator connected to said third logic unit to control the component ratio ''''Vr, r 2'''' having the next greater influence.
 7. A regulating device according to claim 6, wherein said fourth control unit is connected to a fourth logic unit, an alarm device connected to the output of said fourth logic unit, a third integrator connected to the output of said fourth logic device to control the prescribed component ratio ''''Vr, r 3'''' having the greatest influence.
 8. A regulating device according to claim 7, including a calculating device for determining the prescribed component ratios ''''Vr'''' connected to said first, second and third integrators and receiving input from said X-ray fluorescence analyzing device and a premixture charge measuring device connected to said calculating device.
 9. A regulating device according to claim 8 in which said first, second and third integrators are connected to said theoretical value indicator, a residue content device for the determination of a component residue content ''''Rg'''' connected to said theoretical value indicator and a calculating device calculating the mean value ''''Ki'''' of the component contents ''''Ki'''' of the premixture determined in the analysis supplying an input to said residue content device.
 10. A regulating device according to claim 9, wherein said residue content calculating device includes a fourth integrator which sums up the partial contents ''''Ki'''' of the components and a differential device which subtracts the summed up partial contents from the total content and further includes an analyzing device which averages the residue contents ''''R.'''' 